Mauricio Venegas

Long-term treatment with cisapride and antibiotics in liver cirrhosis: effect on small intestinal motility, bacterial overgrowth, and liver function

OBJECTIVES:Altered small-bowel motility, lengthening of the orocecal transit time, and small-intestinal bacterial overgrowth have been described in patients with liver cirrhosis. These changes might be related to the progressive course and poor prognosis of the disease. We investigated the effect of a long-term treatment with cisapride and an antibiotic regimen on small-intestinal motor activity, orocecal transit time, bacterial overgrowth, and some parameters of liver function.METHODS:Thirty-four patients with liver cirrhosis of different etiology entered in the study. They were randomly allocated to receive cisapride (12), an alternating regimen of norfloxacin and neomycin (12), or placebo (10) during a period of 6 months. At entry and at 3 and 6 months, a stationary small-intestinal manometry was performed, and orocecal transit time and small-intestinal bacterial overgrowth were also investigated using the H2 breath test. Liver function was estimated with clinical and laboratory measurements (Child-Pugh score).RESULTS:After 6 months, both cisapride and antibiotics significantly improved fasting cyclic activity, reduced the duration of orocecal transit time, and decreased small-intestinal bacterial overgrowth. Cisapride administration was followed also by an increase in the amplitude of contractions. No statistically significant variations in these parameters were observed with placebo. An improvement of liver function was observed at 3 and 6 months with both cisapride and antibiotics.CONCLUSIONS:Long-term treatment with cisapride or antibiotics reversed altered small-intestinal motility and bacterial overgrowth in patients with liver cirrhosis. These findings suggest a possible role for prokinetics and antibiotics as a modality of treatment in selected cases of decompensated cirrhosis.

IL28B polymorphisms associated with therapy response in Chilean chronic hepatitis C patients

AIM To analyze the association of three IL28B single nucleotide polymorphisms with response to therapy in Chilean patients infected with hepatitis C virus (HCV). METHODS We studied two groups of patients with chronic HCV infection (genotype 1), under standard combined treatment with pegylated interferon plus ribavirin. One group consisted of 50 patients with sustained virological response, whereas the second group consisted of 49 null responders. In order to analyze the IL28B single nucleotide polymorphisms rs12979860, rs12980275 and rs8099917, samples were used for polymerase chain reaction amplification, and the genotyping was performed by restriction fragment length polymorphism. RESULTS The IL28B rs12979860 CC, rs12980275 AA and rs8099917 TT genotypes were much more frequently found in patients with sustained virological response compared to null responders (38%, 44% and 50% vs 2%, 8.2% and 8.2%, respectively). These differences were highly significant in all three cases (P < 0.0001). CONCLUSION The three IL28B polymorphisms studied are strongly associated with sustained virological response to therapy in Chilean patients with chronic HCV (genotype 1).

IL-23R Arg381Gln polymorphism in Chilean patients with inflammatory bowel disease

UNLABELLED Crohns disease (CD) and ulcerative colitis (UC) are multifactorial diseases with a genetic background. Recent results have shown that a non-synonymous, single nucleotide polymorphism (rs11209026, c.1142G>A, p.Arg381Gln) located in the IL-23R gene is associated with inflammatory bowel disease (IBD). The prevalence of IBD is rapidly rising in Chile and there is no information about the frequency of this polymorphism in the Chilean population. AIM To assess the distribution of DNA variants in the IL-23R gene in Chilean patients with IBD. METHODS We studied 100 IBD patients (38 CD and 62 UC) and 59 healthy controls. IL-23R Arg381Gln (G1142A) was genotyped by the polymerase chain reaction and restriction fragment length polymorphism assay. Clinical and demographic features were characterized. RESULTS The IL-23R genetic variant did not have an association with IBD in Chilean patients. This polymorphism was present in 5.2% of the control group and 5% of IBD patients (7.9% for CD and 3.2% for UC) (p > 0.05). CONCLUSIONS These results suggest that the IL-23R Arg381Gln seems not to be involved in the genetic predisposition to IBD in a Chilean population, and confirms that there are ethnic differences in the genetic background of IBD. Replication studies by independent groups are necessary to elucidate the contribution of susceptibility genes to IBD in different ethnic populations.

Phylogenetic analysis of hepatitis B virus genotype F complete genome sequences from Chilean patients with chronic infection

Molecular epidemiological data concerning the hepatitis B virus (HBV) in Chile are not known completely. Since the HBV genotype F is the most prevalent in the country, the goal of this study was to obtain full HBV genome sequences from patients infected chronically in order to determine their subgenotypes and the occurrence of resistance‐associated mutations. Twenty‐one serum samples from antiviral drug‐naive patients with chronic hepatitis B were subjected to full‐length PCR amplification, and both strands of the whole genomes were fully sequenced. Phylogenetic analyses were performed along with reference sequences available from GenBank (n = 290). The sequences were aligned using Clustal X and edited in the SE‐AL software. Bayesian phylogenetic analyses were conducted by Markov Chain Monte Carlo simulations (MCMC) for 10 million generations in order to obtain the substitution tree using BEAST. The sequences were also analyzed for the presence of primary drug resistance mutations using CodonCode Aligner Software. The phylogenetic analyses indicated that all sequences were found to be the HBV subgenotype F1b, clustered into four different groups, suggesting that diverse lineages of this subgenotype may be circulating within this population of Chilean patients. J. Med. Virol. 83:1530–1536, 2011.

Prevalence of hepatitis B virus genotypes in chronic carriers in Santiago, Chile

The eight genotypes (designated A–H) of hepatitis B virus (HBV) display distinctive geographical distribution worldwide, with genotypes A, D and F frequently detected in South America. To determine the prevalence of HBV genotypes in Santiago, Chile, 131 samples from chronic carriers were used for PCR amplification, and genotyping was performed by RFLP. The results indicated that genotype F was the most prevalent among HBV carries (84% of the cases), whereas genotypes A, B, C and D were found at a prevalence of 3.8, 3.8, 6.1, and 2.3%, respectively. We discuss these data in the complex scenario of HBV epidemiology.

Effects of adrenalectopmy on the stress-induced changes in ovarian sympathetic tone in the rat

A 3-wk period of stress promotes the development of ovarian cysts in rats apparently mediated by increased sympathetic nerve activity and ovarian steroid secretion. After 11 wk of stress, these parameters are indistinguishable from nonstressed control rats. To study adrenal contribution, we adrenalectomized rats and studied the effect of 3-wk of cold/restraint stress (1.5 h/d) on them compared to intact animals. Adrenalectomy (ADX) increased ovarian norepinephrine (NE) release, the content of β-adrenergic receptors (βAR) and basal, but not isoproterenol (Iso)-induced, androgen secretion. Stress to intact animals increased NE release, decreased βAR content, and Iso-induced, but not basal, androgen secretion from the ovary. ADX did not modify the response to stress. We propose a tonic inhibition by the adrenal gland on nerve activity of ovarian nerves. Stress overrides this inhibitory effect, and nerve activity downregulates βAR, decreasing ovarian steroid secretion.

Full-Genome Sequence of a Hepatitis B Virus Genotype F1b Clone from a Chronically Infected Chilean Patient

ABSTRACT The hepatitis B virus (HBV) is a DNA virus belonging to the Hepadnaviridae family. Viral isolates have been classified into 10 genotypes, named from A to J, and several subtypes. We report the full-genome sequence from a single molecular clone of HBV genotype F1b, amplified from a chronically infected Chilean patient.

[Hepatitis E virus seroprevalence: a reappraisal].

Reported seroprevalence of hepatitis E virus (HEV) in developed countries is between 0.3-53%. Published data relies on the assays used and its technical performance. Sensitivity on new available tests has improved, which has changed HEV seroprevalence around the world. We re-evaluated retrospectively, 178 serum samples of patients with previous anti HEV IgG determination between 2009 and 2012. Initial analysis was performed with ELISA kit Genelabs (Singapore), with 7.3% positivity. The reevaluation was done with ELISA kit AccuDiag TM HEV-IgG (Diagnostic Automation, United States), with reported sensitivity and specificity over 99.8%. With the new assay, 32.6% positive samples were found, significantly greater to the previous result (p<0.001) (4.5 times more). There were no differences in gender but a significant association between age and HEV IgG seropositivity was found (p<0.001). This suggests that previous testing might have underestimated HEV seroprevalence in Chile, which should be reevaluated using the new available test.

Replication of a chronic hepatitis B virus genotype F1b construct

Genotype F is one of the less-studied genotypes of human hepatitis B virus, although it is widely distributed in regions of Central and South American. Our previous studies have shown that HBV genotype F is prevalent in Chile, and phylogenetic analysis of its full-length sequence amplified from the sera of chronically infected patients identified it as HBV subgenotype F1b. We have previously reported the full-length sequence of a HBV molecular clone obtained from a patient chronically infected with genotype F1b. In this report, we established a system to study HBV replication based on hepatoma cell lines transfected with full-length monomers of the HBV genome. Culture supernatants were analyzed after transfection and found to contain both HBsAg and HBeAg viral antigens. Consistently, fractionated cell extracts revealed the presence of viral replication, with both cytoplasmic and nuclear DNA intermediates. Analysis of HBV-transfected cells by indirect immunofluorescence or immunoelectron microscopy revealed the expression of viral antigens and cytoplasmic viral particles, respectively. To test the functionality of the ongoing viral replication further at the level of chromatinized cccDNA, transfected cells were treated with a histone deacetylase inhibitor, and this resulted in increased viral replication. This correlated with changes posttranslational modifications of histones at viral promoters. Thus, the development of this viral replication system for HBV genotype F will facilitate studies on the regulation of viral replication and the identification of new antiviral drugs.

Genotype F of hepatitis B: response to interferon

BACKGROUND The relevance of HBV genotype diversity on interferon (IFN) therapy outcome in chronic hepatitis B patients has recently been highlighted. Data available for genotype F is poor. The aim of this work was to analyse the response of HBV genotype F to treatment with IFN. Additionally, response was analysed according to the role of single nucleotide polymorphisms (SNPs) near to the IL28B gene. METHODS A total of 29 HBeAg-positive patients with chronic infection were included with a median age 47 (18-68) years. Of them, 27 were male. One patient was treated with standard IFN-α for 16 weeks, 6 patients received PEG-IFN-α2a 180 μg weekly for 24 weeks and 22 patients for 48 weeks. Response to treatment was defined as loss of HBeAg, anti-HBe seroconversion and decline of HBV DNA level to below 3 log of baseline (IU/ml) at the 6-month of follow-up. The SNPs rs12979860, rs12980275 and rs8099917 were studied by PCR-RFLP. RESULTS The overall response was obtained in 18 (62%) patients, including one patient who was treated with standard IFN. Additionally, a total of 9 (31%) patients cleared HBsAg, with appearance of anti-HBs. The viral load was undetectable in all of these patients. The same IL28B variants associated with IFN response in HCV infections were also more frequently found in HBV patients compared with non-responders. CONCLUSIONS Our study indicates that treatment with IFN is effective in patients with HBV genotype F.